BadImageFormatException：无法加载文件或程序集...格式错误 - 仅适用于Web应用程序

Question

I am working on a Web Application on a Windows 8 64 bit machine using multiple existing libraries. I want to use two C# DLLs referencing one native DLL. Both C# DLLs are compiled for 64bit usage and tested in test applications. My web application references both C# DLLs and is supposed to run on IIS 8. I added the two C# DLLs as references to the project and the native DLL manually to the bin folder of the web app. Whenever I build and run the solution I get the exception shown in the title. I know that this is a sign for a problem regarding 32 bit and 64 bit code running in one process. Therefore I tried all different build configurations but the result never changed.

I created a console application doing exactly what I'm trying in the web app and it worked flawlessly. The Web application with the exact same settings however throws the exception, this is what is really confusing to me.

What I tried so far:

• Change application pool setting to "enable 32-bit applications"
• Build all DLLs with Any CPU, 64Bit or x86 target
• Check the corflags of all DLLs

I can provide an export of the project to everybody willing to help me get this configuration running!

I really appreciate every bit of help!

Answer 1

I presume you tried with setting Target Platform (Build option in project properties)? Also, take a look at this article: http://www.codeproject.com/Articles/383138/BadImageFormatException-x86-i-x64

Answer 2

I got the same issue on my application. It was fixed after I perform the following:

* Granting permission for the "Anonymous" user in my web site folder.
* Changing the application pool from ".NET v4.5 Classic" to ".NET v4.5".

Answer 3

All I can offer is some help in determining what isn't loading. If it's a dev server it might be worthwhile to install the appropriate sdk to use the Fusion Log Viewer . If that isn't an option you can turn on assembly binding logging from the registry as follows:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Fusion]
"LogFailures"=dword:00000001
"LogPath"="c:\\bindFailureLogs\\"

just be sure to turn it off when you're done, there is a performance penalty using the assembly bind logging. Make sure the folder exists before you enter the registry key and recycle the application pool of the application for the logging to start. This will provide you a detailed list of what dll (or dependency since it's not always readily apparent if it's a dependancy or the dll listed in the error message) didn't load and where it tried to load it from.

Your partitioning of the applications fixing the problem suggests that there are multiple dependencies on the assembly targeting different versions and since only a single version of an assembly can be loaded into an app domain some dependency isn't being satisfied. For managed assemblies you could use an assembly binding redirect , but I don't know what the unmanaged equivalent of that would be if it even exists.